I buy a kingsize block of 70% cocoa chocolate regularly. I have noticed that Pak’n’Save regularly swaps about which chocolate line is on special — some weeks all Whittakers blocks are $2.98, some weeks all Cadbury’s are $2.98.
Today I noticed that the Cadbury’s 70% Old Gold bars, and all their other “premium” high cocoa bars, are only 220g, not 250g like their less chocolatey brethren. Whereas all the Whittakers bars, irrespective of cocoa content, are 250g. So even at $3.15, the current Whittakers price, Whittakers Dark Ghana is a better buy (per gram) than Cadbury Old Gold.
Moral: always check the unit cost. And to check the unit cost, assess the unit you’re measuring — in this case, weight of chocolate bar. Not all “king size” blocks are equal.